Attempting matrix build

Author: Gareth Ellis

.github/workflows/ci.yml

@@ -3,12 +3,19 @@ name: CI
 on: [push, pull_request]
 
 jobs:
-  build:
-    runs-on: ubuntu-latest
-
+  run:
+    runs-on: 'ubuntu-latest'
+    strategy:
+      matrix:
+        php-versions: ['8.1', '8.2', '8.3']
+        phpunit-versions: ['latest']
     steps:
-      - uses: actions/checkout@v1
-
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php-versions }}
+          extensions: intl
+          tools: phpunit:${{ matrix.phpunit-versions }}
       - name: Composer install
         run: composer install --prefer-dist